The present invention relates to foldable dehydrated food containers. More specifically, it relates to a method for producing a container which may be folded flatly and then unfolded to a final form which is void of unsightly wrinkles and has a planar bottom which may be placed in a stable fashion on a flat surface.
Recently, many instant (dehydrated) foods, such as powdered juice, milk, cream, jam, and other foods in the state of powder or liquid, as well as gel-state instant foods, have been developed. These instant foods are packaged commonly not in a large quantity but in a small quantity to provide a single individual portion. Because the package quite possibly will be dispensed by an automatic system, it is required that the volume of the folded containers must be rather reduced to give the convenience in the carriage, treatment and management of the containers. Also the container should give safety in use after the container is filled, i.e., it should not tip or spill easily. Additionally, the container must be both inexpensive in its materials and also easy to manufacture. However, until now, there is no container that satisfies the expansion of the container, the flatness of the bottom of the container, and easy manufacture.
At present, if the container is made of paper, thin plastic sheet, or a cloth paper coated with aluminium, it is possible to obtain a container having a flat bottom, because such material can be folded or expanded. However, even when the container is made of such material the circumference forming the bottom of the container cannot be folded or deformed. This is so because the contact between the circumference along the bottom and the side wall(s) of the container has no change, hence, when the circumference is compressed, there appears a lot of wrinkles and scars along the location where the circumference of the bottom and the side wall of the container are joined. Thus, when the container is expanded to store the foods, the container cannot provide good expansion because such container cannot be returned to its original state before expansion. It is a known fact that, according to geometrical theory, a smooth circumference between the bottom and side wall cannot be obtained in a compressed state.